Lapping machine



J. R. RICKETTS.

LAPPING MACHINE.

APPLICATION FILED MAR. 6. I920.

1,420,75 1 Patented m 27, 1922.

2 SHEETS-SHEET I.

J. R. RICKETTS.

LAPPING MACHINE.

uwucmou FILED rm. 6, 1920.

1 ,420,75 1 Patented June 27, 1922.

2 SHEETS-SHEET 2.

3 nmmkw ammo UNITED STATES JAMES R. RICKETTS, OF KANSAS CITY. MISSOURI.

LAPPING MACHINE.

Application filed March 6, 1920.

T 0 all whom it may concern:

Be it known that I. JAmcs R. Ricknrrs, a citizen of the United States, residing at Kansas City, Missouri in the county of Jackson and State of Missouri, have invented certain new and useful Improvements in Lapping Machines; and I do declare the following to be a full, clear, and exact description of the invention such as will onable others skilled in the art to which it appertains to make and use the same. reference being had to the accompanying drawings, and to the letters and figures of reference marked thereon, which form a part of this specification.

This invention relates to lapping: machines and particularly to a machine in which the two main members of an engineers valve, such as is used in controlling fluid on a locomotive, trolley car and the like, may be faced or ground so as to effect a close fit between the valve and its seat.

Engineers valves consist of ported seat members which co-operate with COHIplOIHQXI- tary rotating disk members adapted to be moved about an axial center so that when certain ports in the seat member coincide with certain parts in the movable or disk member, communication is established be tween a source of fluid supply and a source of fluid application.

The fluid medium is usually air and after the valves have been in use for some time. the lit is impaired to the extent that the air may leak. It then becomes necessary to grind the valve, the valve seat or both so that the original status-of the two main members of the valve will be reestablished.

The operation is called lapping and in the nomenclatureof the shop is termed valve grinding. The operation of lapping or ,g'rinding" a valve is more or less delicate since the abutting faces of the complementary members must lie in true parallel planes in order to obtain a perfect fit of the movable element upon its seat. Since it is the practice to lap or fit thetwo members together by effectinga rubbing: action between their meeting faces (generally in the presence of an abrasive) it is essential that the paths of movement of the operated member or members he not traversed in uniformly recurring directions since if the movement of the operating member or members follows the same path or paths in regular sequence or sequences, there is liable to Specification of Letters Patent.

Patented June 27, 1922.

Serial No. 363,686.

be formed grooves or inequalities in either ation being of sufficient delicacy to insure a substantially perfect fit between the face of the seat and the face of the co-operative member and the generic principles as well as the specific construction of the invention will be referred to hereinafter, it being understood that the particular details of construction of the invention need not essentially be followed in all embodiments which the invention is capable of partaking. the particular form shown being simply illustrative of the preferred form of the device for accomplishing the desired result.

In the drawings.

Fig. I is a view partly in perspective and partly in section, showing the preferred form of lapping" machine.

Fig. II is a vertical. longitudinal, sectional view through the casing. the oper ating elements being shown partly in elevation and partly in section.

Fig. III is a disassociated view of the two end elements of an engineers valve adapted to be ground or lapped by the mechanism shown in Figs. I and II. and

Fig. IV is a diagrannnatic view showing the seat member. the valve member and the co-(merating parts of the machine which effect certain novel movements of the two elements.

In the present embodin'ient of the inven tion I have shown a shallow base .l'in which is mounted a drive shaft 2. carrying a pulle v 3 over which passes a belt 4, driven from any suitable Source. The manner of driving the shaft 2 is immaterial and I desire it to be understood that I do not wish to be limited to the particular arrangement shown.

On the shaft 2 is a friction disk 5 against one side of which presses the end of a coil spring 6. the other end of the spring bearing against the collar 7 on the inside of the case I. The expansion spring 6 tends to maintain the friction disk 5 in driving engagement with the periphery of the disk 8 on the shaft 9, mounted in the vertical bearing 10 on the case 1 so that when the shaft 2 is driven, motion will be communicated to the disk 8 and to the shaft 9. The shaft 9 carries at its upper end a table of support 11, which is axially mounted upon the shaft 9 and is adapted to rotate in the direction of the arrow. The table 11 is adapted to receive one of the main valve elements, for example, the valve seat 12 (Fig. 111), which may be of approved construction and which is preferably mounted in the gig 13, as clearly seen in F IV, the valve seat member 12 being held in non-rotative position with respect to the table 11 and the vertical axis of the valve seat 12 and slightly off set with respect to the axis of the table or disk 11 and shaft 9, the purpose of which will be presently explained.

Mounted on the shaft 9 above the friction disk 8 is a pulley 1 1, around which passes a belt 15, driving the pulley 16 on the vertical shaft 17 in the bearing 18, carried by the base 1. At the upper end of the shaft 11" is an eccentrically disposed pin or connection 19, which imparts motion to a linl: 2O having a bifurcated end 21 to removably engage the arm or lever 22 of the valve mem ber actuator 23. The member 22 is secured to the bifurcated portion 21 by a ren'iovablc pin 24 so that the members 20 and 22 may be disconnected when desired. The lever or handle 22 of the actuator 23 loosely rests in the bifurcated portion 25 of a vertical rock. shaft 26 supported in the upper end of a standard or support 27 so that when the pulley l6 and the shaft 17 are rotated, an oscillatory motion will be imparted to the mem. ber 23 The member 23 is shown as consisting of a ring slightly greater in diameter than the diameter of the rotating; ilve incur ber 28, which is confined therein so that it will loosely float upon the surface of the member 12 of the engineers valve. The member 28 may be of standard construction. as will be well understood By reference to Fig. Ill. it will be apparent that the prob em to be solved by the machine is to grind in or lap the surfaces 29 and 30 of the respective members so that they will be provided with accurately ground, uniformly parallel face surfaces to permit them to accurately lit when in place and thereby eliminate leakage 01 the air or other fluid passing through their respective orts.

The oscillatory movement imparted to the member 23 will be such that the member 28 will freely float over the surface 29 of the member 12 without traversing any particular path of movement with uniform rccurrence. The interior edge 31 of the ring or yoke member 23 is adapted to frictionally engage the periphery 32 of the member 28 and during the osci latory movement of the member 23, the member 28 will not only oscillate so as to revolve about the axis of the member 12 but it will also be caused to rotate on its own axis on account of the friction between the edges 31 and 32. in actual 1 racticc the table 11 and the valve seat mem ber 12 rotate in the same direction; that is, according to the illustrated embodiment of the machine, in a contra-clockwise direction. The member 23, however, oscillates in a clockwise direction and the friction of the inner wall 31 thereof against the periphery 32 of the member 28 causes the member 28 to rotate in a contra-clockwise direction, or in the direction of the valve seat member 12 so that while the member 28 rotates in the same direction as the member 12, it revolves in a direction opposite to the member 12.

By reference to Fig, 1V, it will be observed that the member 12 rotates about a fixed axis, whereas the member 28 not only rotates upon its own axis but revolves about the axis of the member 12 and that it is free to Heat within the actuator or yoke 25 so that it moves over the member 12 in constantly changing paths. rotating about. variable centers and there is an unimpeded free movement of the member 28 over the member 12, the member 28, of course, being confined within certain bounds by the yoke or member 23.

r itlention is also called to the fact that while the member 12 is slightly offset from the axis of the shaft 9 and table '11, it, in

effect, rotates about its own axis since the cccei'itricity is slight, the abrading action, however, beinp performed by the floating valve iucn'rbcr 28, the weight of which is sullicieu't to perform the grinding action, this being an iinportai'it feature since the valve member 28 will auttunatically grind itself into the seat so that the faces 29 and 5U will be substantially parallel to insure a perfect lit between. the two parts.

l convenience I may apply a shifter consisting of the shaft 33, having a cam 34: thereon. which is adapted to contact with the face 35 of the pulley 3, fixed on shaft 2 so that a longitudinal movement may be im- P3111641 to the shaft 2 to shift the friction wheel 5 from the periphery of the friction wheel 8, the shaft being adapted to be turned by a ,lCl'lUTlQd head 36 so that the finger 37 may engage in one of the openings 38, there being; also a friction spring 39 provided to hold it and the finger 1-0 in lhe hole or depression 238 into which it is introduced.

Attention is also called to the fact that the belt 15 on pulleys 14 and 16 drives the shafts i) and 17' in the same direction (according to the illustration, contra-clockwise) but the actuator 23 oscillates in an opposite direction due to the fact that the bifurcated bean inn reverses the movement imparted to the curl by the stud or pin 19. I prefer to employ a loose belt 15 because the slippage of the belt will break up any tendency to regularity of movement of the member 28 through fixed paths over the surface of the member 12, thereby eliminating the liability of scoring either of the elements 12 or 28.

Since the oscillations of the member 23 are in directions opposite to the direction of rotation of the member 12 and in view of the fact that the member 28 will rotate on its own axis in the direction of movement of the table 11 and the member 12 while being revolved about the axis of the table 11, there will be a slight slip between the faces 29 and 30 due to the fact that a lag is set up between the two surfaces 29 and 30. That is. while the member 28 rotates in the same direction as the member 12, it does so at .a slower speed. This I consider important as it tends to render the abrading material effective. If, after the grinding in operation has been completed. it is desired to polish the faces of the members 12 and 23 or similar elements. this can be accomplished by wiping off all the abrading material and continuing the operation with a lubricant only between the faces 29 and 30.

There is also an advantage in hinging the lever 22 to the end 21 of the link 20 and mounting the same in the bifurcated portion 25 of the shaft 26 as this construction enables the operator to swing the member 23 upward out of the way to apply and remove the member 12 to the table 11.

The mechanism as shown is so constructed that the weight of the valve alone bears upon the ahrading material. \Vhere balanced valves are used, the grinding in can be very efficiently accomplished without any exterior pressure. IVhere unbalanced valves are employed. that is. where one side of the valve is heavier than the other, it may be desirable to equalize the weight over the entire valve and to this end a compensating weight may be employed so that the pressure will be equal on all parts of the two faces. This is an obvious expedient, however. and n0 structure is shown for accomplishing such a result.

It will be apparent from the foregoing that the device is simple in construction and that it will readily perform the function for which it is intended.

IVha-t I claim and desire to secure by Letters-Patent is: I

1. In a, device of the class described, a 1'0- tating table, an oscillating member movable parallel with the table and having a valve member receiving yoke comprising a ring of greater diameter than the diameter of the valve member.

2. In a. device of the class described, a rotating table, and an oscillating member movable parallel with the table and having a valve member receiving yoke comprising a ring of greater diameter than the diameter of the valve member, said yoke having a valve contacting edge to cause the valve member to rotate by frictional contact therewith during the oscillatory movement of the yoke.

3. In. a device of the class described, a rotating table, an oscillatory valve member actuator, and means on the actuator for rotating the valve member.

4. In a device of the class described, a rotating table to receive a valve seat, an oscillatory valve actuating member above the table, and means for rotating a valve member as it is oscillated by the actuator.

5. In a device of the class described, a valve member supporting rotating table, and means for loosely engaging a complementary valve member, said means being effective in sliding the complementary valve member in curved paths over the surface of the first mentioned valve member.

6. In a device of the class described, a casing, a horizontal shaft in the casing, means for driving said shaft, a friction disk on the shaft, a vertical table supporting shaft, a friction disk on said shaft co-operating with the first named friction disk, a pulley on the vertical table supporting shaft, 2. vertical shaft, a. pulley thereon, belt connections between the two pulleys, and an oscillatory member connected to the vertical shaft and above the table, supported by the table supporting shaft.

7. In a device of the class described, a casing, a horizontal shaft in the casing. means for driving said shaft, a friction disk on the shaft, a vertical table supporting shaft, a friction disk on said shaft co-operating with the first named friction disk, a pulley on the vertical table supporting shaft, a vertical shaft, a pulley thereon, belt connections between the two pulleys, and an oscillatory member connected to the vertical shaft and above the table, supported by the table supporting shaft, said oscillatory member including a ring-shaped yoke to receive a valve member to co-operate with a corresponding valve member on the table.

8. In a device of the class described, a rotating table. means for driving said table, a vertical shaft, means receiving power from the table, driving means to rotate the shaft, and an oscillatory member above the table and having a hinged connection with the vertical shaft whereby the oscillatory member may be swung in the vertical plane away from the table.

9. In a device of the class described, a rotating table, an oscillatory, valve-receiving ring above the table and having valve engaging means to engage the periphery of the valve so as to rotate it as it is oscillated by the ring, and means for actuating the ring.

In testimony whereof I affix my signature.

JAMES R. BIGKETTS. 

